高压氧减轻沙土鼠脑缺血时脑组织间隙水肿机制的研究

Study on the mechanism of alleviating intercerebral edema in gerbils after cerebral ischemia by hyperbaric oxygen

目的 探讨高压氧减轻脑组织间隙水肿的作用机制。方法 采用激光多谱勒和电镜方法 ,测量沙土鼠软脑膜微血管管径和观察脑微血管超微结构的变化。结果 脑缺血 30min再灌注 ,脑微动、静脉明显扩张 ,同时 ,血管周隙严重水肿。脑缺血的沙土鼠在高压氧 ( 0 .2MPaO2 )下暴露 30min ,微动脉收缩 ,微静脉无明显变化 ,血管周隙水肿消退。结论 在高压氧状况下 ,脑微动脉收缩 ,毛细血管内血压下降 ,有利于组织液吸收 。

Objective To study the mechanism of alleviating intercerebral edema in cerebral ischemic gerbils by hyperbaric oxygen. Methods The diameters of microvessels of gerbil's pia mater were measured with laser Doppler and the ultrastructure of microvessels of gerbil's cortex was observed under electron microscope. Results The microarteries and the microveins were obviously dilated when reperfused after 30 min cerebral ischemia, and meanwhile the edema was severe around the microvessels. After the ishemic reperfused gerbils were exposed to 0.2 Mpa O 2 for 30 min, the cerebral microarteries contracted but no changes could be found in the microvein and the edema around the microvessels resolved. Conclusion During hyperbaric oxygen exposure, the cerebral microarteries contract and the capillary pressure decreases, thus favorate the absorption of tissue fluid and alleviate the intercerebral edema.